Feed mechanism for sewing machines



Dec. 22, 1964 J. CHUDNER 3,162,158 FEED MECHANISM FOR SEWING MACHINES Filed July 2, 1963 4 Sheets-Sheet l i X; INVENTOR. JosEPH CHODNER ATTORNEY J. CHUDNER FEED MECHANISM FOR SEWING MACHINES Dec. 22, 1964 4 Sheets-Sheet 2 Filed July 2, 1963 INVENTOR.

JOSEPH CHUUNER ATTORNEY Dec. 22, 1964 J. CHUDNER FEED MECHANISM FOR SEWING MACHINES 4 Sheets-Sheet 3 Filed July 2, 1963 INVENTOR.

JOSEPH CHU N E ATTORNEY Dec. 22, 1964 J CHUDNER 3,162,158

FEED-MECHANISM FOR SEWING MACHINES I Filed July 2, 1963 4 Sheets-Sheet 4 FIG. /0 7, H61 7/ INVENTOR.

JOSEPH CHUDN ER BY ATTORNEY United States Patent Ofifice 3,lhZ,l5.3 Patented Dec. 22, 1%64 3,162,158 F EED MEQHANISM FOR SEWING MACHINES Joseph Chudner, 2%; Enlighten Beach 8 St., Brooklyn, Ni". Fiied .Iuly 2, 1963, Ser. No. 292,374 8 Claims. ({Il. 112-207) This invention relates to sewing machines, and more particularly to feed devices for transporting work material from the front of the sewing machine through the stitching area thereof toward the rear of the machine, this invention being an improvement over the feed mechanism disclosed in my coending earlier filed application Serial No. 94,120, filed March 6, 1961, and now Patent No. 3,099,974.

The work to be stitched usually comprises two or more separate pieces of fabric disposed in superposed relation to one another, the fabric being transported from front to rear of the sewing machine beneath the needle and presser foot by means of an underlying feed dog which moves along a generally eliptical path in a vertical plane and penetrates through the upper surface of the work support during that portion of the cycle in which it is moving rearward. The food dog thus engages the undersurface of the lowermost ply of fabric to be stitched, and this, together with the downward pressure exerted upon the upper ply of fabric by the presser foot can induce slippage between the upper and lower plies, this being particularly true with smooth surfaced or slippery materials. The feed mechanism according to the invention prevents such slippage by providing an overhead auxiliary feed which cooperates with the sewing machine feed to cause simultaneous top and bottom feeding and avoidance of such slippage.

The feed mechanism according to the present invention dilfeis from that disclosed in my co-pending application above referred to in that in the present invention the weight of the feed device is carried by the fixed structure of the sewing machine rather than by the presser foot bar, and in that the presser foot structure is separate from the feed mechanism so that a plurality of different types of presser feet may be used as desired with the auxiliary'top feed mechanism of the invention. Accordingly, it is a primary object of this invention to provide a novel top feed mechanism for sewing machines which operates in unison with the sewing machine feed dog to transport the work past the reciprocating needle from the front of the machine towards the rear thereof in such manner that the several plies of multiple ply work being fed have no tendency toward relative slippage therebetween.

Another object of this invention is to provide a novel auxiliary top feeding mechanism for use with sewing machines which is quickly and easily attachable to and detachable from the sewing machine with which it is.

to be used and which includes means for rigidly supporting the auxiliary feed mechanism from the non-moving parts of the sewing machine to thereby eliminate stresses on the working parts of the sewing machine.

Still another object of this invention is to provide a novel auxiliary top feed mechanism for sewing machines as aforesaid in which the top feed portion which actually engages the work interfits with a presser foot part securable to and carried by the presser foot bar but which presser foot is not connected to the top feed mechanism.

The foregoing and other objects of the invention will become clear from a reading of the following specification in conjunction with an examination of the drawings, wherein:

FIGURE 1 is a rear elevational view of a sewing machine with the auxiliary top feed mechanism secured thereto;

FIGURE 2 is an end elevational view of the sewing machine and top feed mechanism of FIGURE 1 as would be seen when looking into the right hand or working end of the machine;

FIGURE 3 is similar to FIGURE 2, differing therefrom only in that the presser foot is illustrated in the down position whereas in the showing of FIGURE 2 the presser foot is raised;

FIGURE 4 is a vertical sectional view through the auxiliary top feed mechanism as would be seen when viewed along the line 44 of FIGURE 1;

FIGURE 5 is an enlarged top view of the presser foot and feed dog portion which interfits therewith to produce the top feeding motion as would be seen when viewed along the line 5-5 of FIGURE 4;

FIGURE 6 is an enlarged rear view of the auxiliary top feed mechanism, partly in section and partly in elevation, as would be seen when viewed along the line 6--6 of FIGURE 4;

FIGURE 7 is a front perspective view of the auxiliary top feed mechanism as detached from the sewing machine;

FIGURES 8 and 9 are a rear perspective of the auxiliary top feed mechanism shown in FIGURE 7 with the presser foot portion separated from the auxiliary feed dog drive portion; and

FIGURES 10'through 13 are similar to the showing of FIGURE 3 excepting that a portion of the side plate and support structure has been. sectioned away to reveal the inner construction of the feed in a manner similar to that of FIGURE 4, FIGURES 10 through 13 illustrating four positions of the continuous sequence of feeding motion of the feed dog of the auxiliary top feed mechanism.

In the several figures, like elements are denoted by like reference characters.

Turning now to an examination of the figures, and firstly to FIGURES 1 to 9, the invention is illustrated in organization with a sewing machine of the ordinary and Well-known type. The illustrated sewing machine ineludes a work support to which is secured a sewing machine bracket having a vertical arm 21 and horizontal arm 22 which support a stitching head 23. The work support 20 is apertured beneath the stitching head to provide a throat covered by a throat plate 24 which is slotted to permit passage therethrough of the sewing machine feed dog 25 which advances the work to be stitched under the stitching head 23 from front to rear beneath the needle carried by a reciprocable needle bar 26 and under a presser foot supported by a presser foot bar 27 reciprocable within a fixed position sleeve 28. The feed dog 25 and needle bar 26 are cyclically operated by mechanism mounted within the sewing machine bracket arms and beneath the work support 20 and which is coupled to the fiy wheel 29 driven by a suitable power mechanism such as an electric motor.

The present invention includes a top feed mechanism designated generally as 30 detachably secured at its forward end to the sewing machine by means to be hereinafter described and secured at its upper end by a bracket structure designated generally as 31. The feed mechanism 30 is drivable in timed relationship to the motion of the sewing machine feed dog 25 by means of a drive mechanism which couples the sewing machine fly wheel 29 to the top feed mechanism 3%) and which includes a pair of pulleys 32 and 33 coupled by a drive belt $4, the pulley 33 being mounted upon a common shaft with a fly wheel 35 and terminating in a coupling socket 36. A counterpart to the coupling socket 36, designated as 37, is secured by means of set screw 38 (FIGURE 6) to the top feed drive shaft 39, the coupling sockets 36 and 37 being intercoupled by means of the coupling shaft 46 extending therebetween. The drive shaft carrying the fly wheel 35 and coupling socket 36 is secured to a support bracket 41 by means of fitting 42, the bracket 41 being fixedly secured to and carried by the horizontal arm 22 of the sewing machine bracket by means of the studs 43.

Referring now also to the remainder of the figures, it is observed that the top feed mechanism 343 includes a pair of side plates 4-4 of generally L-shape having vertical and horizontal legs between which are disposed a vertical crank arm 45 and a horizontal crank arm 46 pivotally secured as at 47 at the vertex of the L-shaped side plates 44. The vertical crank arm 45 is provided with an elongated generally centrally extending slot 48, and the horizontal crank arm 46 is similarly provided with an elongated slot 49. Disposed within the crank arms slots are sliders i and 51 mounted on pivots 52 and 53 and free to rotate thereabout While permitting the crank arms to move smoothly relative to the sliders disposed within the associated slots thereof effective to control the motions of the crank arms.

The pivot 53 is vertically shiftable within the elongated slots 54 cut through the sides of the vertical legs of the side plates 44 and securable at a desired position by means of the thumb nuts 55 The pivot 52 is vertically shiftable within the short vertical slots 56 cut through the sides 7 of the horizontal legs of the side plates 44, the opposite ends of the pivot 52 extending outward beyond the side plates 44 and through the depending side legs 57 of a yoke member which has an upper bridging portion 58 extending transversely above the side plates. Disposed fiatwise upon the upper surface of the bridging portion 58 is the end of the horizontal leg of-an L-shaped leaf spring structure 59, the vertex of the leaf spring being disposed about a pin 6%! extending between and secured to the side plates 44. The upper end of the vertical leg of the leaf spring is held by a bolt 61 projected therethrough with a nut 62 threaded upon the end thereof. The spring Sh is variably biased by means of the bolt 61 whose shank is projected freely through a cross-bar 63 keyed to the side plates 44. Rotation of the bolt 61, for example by means of the slotted bolt head, shifts the nut either toward or away from the bolt head to thereby increase or decrease the downward spring bias exerted on the yoke bridging portion 58 by the horizontal leg of the spring 59.

The yoke is thus normally biased downward, as seen in FIGURE 3, so that the pivot pin 52 is positioned at the bottom of the slots 56. Upward pressure exerted on the front end of the horizontal crank arm 45 causes it to pivot about rear pivot 47 and move with the slider 51 and pivot 52 and yoke upward against the bias of leaf spring 59, as seen in FIGURE 2. Release of the upward pressure returns the crank arm downward. Such upward pressure is exerted on the crank arm 46 by the rear end of the presser foot mounting block 64, secured to the presser foot bar 27 by machine screw 65, whenever the presser foot bar 27 is raised by action of the presser foot lever 66, this being clearly seen in FIGURE 2. The top feed dog 67 which is fixedly secured to the forward end of crank arm 46 by machine screw 68 is thus simultaneously raised, and lowered with the presser foot 69 that is pivotally secured to the lower end of the presser foot mounting block 64.

The provision of slots 56 in the side plates 44 is necessary to permit the above-described vertical shifting of the top feed dog 67 since the side plates 44 are rigidly fixed in position by means of the bracket 31 and the clamping block 70, which latter is secured by machine screws 71 to and between the forward ends of the horizontal legs of the side plates 44 with the clamping block itself being slipped about and locked to the presser foot bar fixed sleeve 28 by means of a machine screw 72.

.The upper end of the vertical crank arm 45 is horizontally apertnred, and close fittingly rotatably disposed therewithin is an eccentric 73 within which is fitted and fixedly secured thereto the top feed drive shaft 39. The drive and eccentric are enclosed by a bearing structure '74. Rotation of the drive shaft 3% causes rotation of the eccentric 73 resulting in oscillating motion of the upper and lower ends of vertical crank arm 45 about the pivot 53 and slider 59 with attendant vertical reciprocation of the arm relative to the slider 59. These motions of the vertical crank arm 45 are coupled at the pivot 47 to the horizontal crank arm 46 causing it to slide horizontally in oscillatory fashion relative to its slider 51 while the fore and rear. ends of the horizontal crank arm also oscillate in a vertical sense.

The top feed dog $7 is thus caused to oscillate in an essentially elliptical path in a vertical plane and thereby cooperate with the underlying sewing machine feed dog 25 to move the upper and lower plies of fabric under the stitching head 23. The top feed dog 67 moves downward at its forwardmost point as the machine dog 25 moves upward and then moves rearward together with the machine fecd dog to the rearrnost point of the cycle where the top feed dog 67 moves upward while the machine feed dog 25 moves downward to thereby both disengage from the material being fed, both feed dogs thereafter moving forward, and then continuously repeating the cycle of cooperative motion. Four points in the feeding cycle are illustrated in FIGURES 10 to 13. The top feed dog 67 is vertically adjustable within limits relative to the underlying sewing machine feed dog 25 by reason of the vertical slot 75 cut in the side of the forward end of the horizontal crank arm 45, and is secured in adjusted position by the machine screw 68, this detail being most clearly seen in the showings of FIGURES 5, 7 and 10 to 13.

The top feed mechanism support bracket 31 is of gen erally inverted L-shape having an upper horizontally extending arm 76 and an angularly depending arm 77 pivotally secured at its lower end, as at 78, between the upper terminal cars 79* of the side plates 44. The inner terminal end of the upper horizontal arm 76 is vertically apertured as at $9, and the bracket 31 is secured to the stitching head 23 by projecting the bolt 81 downward through the aperture 89 of the leg 76 and into threaded engagement with the top of the stitching head 23 and thereafter tightening the locking nut 82 on the shank of the bolt 81. Finally, the feed is provided with an oil drip pan 83 extending beneath the crank arm 46 and the lower edges of the side plates 44 to catch lubricating oil and prevent the same from dripping down onto the article being stitched, the pan being detachably secured to the side plates 44 by means of rear projections 84 extending from the latter and the side screws 35.

The rigid physical connection of the bracket 31 and side plates 44 to the stitching head 23 provides a firm support for the entire top feed mechanism 30, and the unbalanced mass of the feed is not supported from the shiftable presser foot bar 27. Synchronization of the top feed dog 67 with the sewing machine feed dog 25 may be effected either by disconnecting the belt 34 until proper positioning has been arrived at or by loosening the set screw 38 which secures the coupling socket 37 to the drive shaft Sh and then retightening the set screw 38 after properly positioning the top feed dog 67. It will of course be also appreciated that ditierent types of presser feet may be utilized with the illustrated top feed mechanism 30 since the presser foot structure is not a part of the feed mechanism but is merely interfitted therewith and can be detached from the presser foot bar and substituted for.

Having now described my invention in connection with a particularly illustrated embodiment thereof, it will be appreciated that variations and modifications of my invention may now occur from time to time to those persons normally skilled in the art without departing from the essential scope or spirit of my invention, and accordingly it is intended to claim the same broadly as well as specifically as indicated by the appended claims.

What is claimed as new and useful is:

1. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaigng from above the material being stitched, drive means carrying said auxiliary feed dog for coupling the latter to the sewing machine power drive effective to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, support means for said drive means detachably fixedly securable to non-moving parts of the sewing machine, means securable to and shiftable with the sewing machine presser foot bar operative to engage said drive means and raise said auxiliary feed dog whenever the sewing machine presser foot is raised and operative to permit lowering of said auxiliary feed dog and disengage from said drive means whenever the sewing machine presser foot is lowered, spring means operative to resiliently bias said auxiliary feed dog toward said sewing machine feed dog, and means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

2. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating witha four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machinefeed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-moving parts of the sewing machine, auxiliary feed dog drive means carried by said support means and having a part thereof engageable and shiftable with means carried by the presser foot bar of the sewing machine, said drive means part engagable and shiftable with the means carried by the presser foot bar carrying said auxiliary feed dog, and said drive means adapted to couple said auxiliary feed dog to the sewing machine power drive effective to operate the auxiliary feed dog with a four Way feed motion to advance the material being stitched from front to rear of the sewing machine, and means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the ewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

3. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-moving parts of the sewing machine,

auxiliary feed dog drive means carried by and movable with respect to said support means and including an oscillatable crank arm engageable and shiftable with means carried by the presser foot bar of the sewing machine, said crank arm carrying said auxiliary feed dog, and said drive means adapted to couple said auxiliary feed dog to the sewing machine power drive effective to operate the auxiilary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, and means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

4. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-moving parts of the sewing machine, auxiliary feed dog drive means carried by and movable with respect to said support means and including an oscillatable crank arm engageable and shiftable with the presser foot of the sewing machine, said crank arm carrying said auxiliary feed dog so that the latter is raised and lowered whenever the sewing machine presser foot is raised and lowered, and said drive means adapted to couple said auxiliary feed dog to the sewing machine power drive being effective to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, means carried by said support and operative upon said crank-arm for biasing said auxiliary feed dog resiliently toward the machine feed dog, and means for synchronizing the four way feed motion of the auxiliaryfeed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

5. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-movingparts of the sewing machine, auxiliary feed dog drive means pivotally carried by and shiftable with respect to said support means and including an oscillatable crank arm the front end of which is engageable and shiftable with means carried by the presser foot bar of the sewing machine, said crank arm carrying said auxiliary feed dog so that the latter is raised. and lowered whenever the sewing machine presser foot bar is raised and lowered, and said drive means adapted to couple said auxiliary feed dog to the sewing machine power drive being efiective to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, means carried by said support and operative upon said crankarm for biasing said auxiliary feed dog resiliently toward the machine feed dog, and means for synchronizing the four way feed motion of the auxiliary feed dog with 7. the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

6. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the Work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-moving parts of the sewing machine, auxiliary feed dog drive means pivotally carried by and shiftable with respect to said support means and including an oscillatable crank arm engageable and vertically shiftable with means carried by the presser foot bar of the sewing machine, said crank arm carrying said auxiliary feed dog and being vertically shiftable between upper and lower limits relative to said fixed support means, biasing means carried by said fixed support means and coupled to said oscillatable crank arm operative to constantly strongly bias said arm and auxiliary feed dog downward toward the said vertically shiftable lower limit so that said auxiliary feed dog is raised against the bias of said biasing means whenever said presser foot bar is raised, said drive means including coupling means for coupling said auxiliary feed dog to the sewing machine power drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, and means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

7. The apparatus as set forth in claim 6 wherein said biasing means includes a spring structure and means for adjusting the spring force exerted on said crank arm by said biasing means. I

8. For external attachment to and use with a sewing machine of the type having a work support, a presser foot bar and a movable feed dog operating with a four way feed motion through the work support to engage from below the material being stitched and advance the same from front to rear of the sewing machine, an attachable and detachable auxiliary feed device comprising in combination, a movable auxiliary feed dog positioned to overlie the sewing machine feed dog in upwardly spaced relation thereto for engaging from above the material being stitched, support means detachably fixedly securable to non-moving parts of the sewing machine, auxiliary feed dog drive means pivotally carried by and shiftable with respect to said support means and including an oscillatable crank arm the front end of which is selectively engageable by and vertically upwardly shiftable with means carried by the presser foot bar of the sewing machine when the presser foot bar is raised, said crank arm fixedly carrying said auxiliary feed dog and pivotally carrying a yoke structure wherein the yoke pivot is verti cally shiftable with said crank arm between upper and lower limits within slots formed in said support means, resilient biasing means carried by said support means and engaged with said yoke operative to bias said yoke and crank arm constantly downward toward the said lower limit so that said auxiliary feed dog is raised against the bias of said biasing means whenever said crank arm is selectively engaged by the raising of the sewing machine presser foot bar, said drive means including coupling means for coupling said auxiliary feed dog to the sewing machine power drive to operate the auxiliary feed dog with a four way feed motion to advance the material being stitched from front to rear of the sewing machine, and means for synchronizing the four way feed motion of the auxiliary feed dog with the four way feed motion of the sewing machine feed dog to cause both said feed dogs to move the material being stitched in the same direction and substantially simultaneously when such material is engaged thereby.

References Cited by the Examiner UNITED STATES PATENTS 2,967,498 1/61 Russell et al l12--207 JORDAN FRANKLIN, Primary Examiner. 

1. FOR EXTERNAL ATTACHMENT TO AND USE WITH A SEWING MACHINE OF THE TYPE HAVING A WORK SUPPORT, A PRESSER FOOT BAR AND A MOVABLE FEED DOG OPERATING WITH A FOUR WAY FEED MOTION THROUGH THE WORK SUPPORT TO ENGAGE FROM BELOW THE MATERIAL BEING STITCHED AND ADVANCE THE SAME FROM FRONT TO REAR OF THE SEWING MACHINE, AN ATTACHABLE AND DETACHABLE AUXILIARY FEED DEVICE COMPRISING IN COMBINATION, A MOVABLE AUXILIARY FEED DOG POSITIONED TO OVERLIE THE SEWING MACHINE FEED DOG IN UPWARDLY SPACED RELATION THERETO FOR ENGAGING FROM ABOVE THE MATERIAL BEING STITCHED, DRIVE MEANS CARRYING SAID AUXILIARY FEED DOG FOR COUPLING THE LATTER TO THE SEWING MACHINE POWER DRIVE EFFECTIVE TO OPERATE THE AUXILIARY FEED DOG WITH A FOUR WAY FEED MOTION TO ADVANCE THE MATERIAL BEING STITCHED FROM FRONT TO REAR OF THE SEWING MACHINE, SUPPORT MEANS FOR SAID DRIVE MEANS DETACHABLY FIXEDLY SECURABLE TO NON-MOVING PARTS OF THE SEWING MACHINE, MEANS SECURABLE TO AND SHIFTABLE WITH THE SEWING MACHINE PRESSER FOOT BAR OPERATIVE TO ENGAGE SAID DRIVE MEANS AND RAISE SAID AUXILIARY FEED DOG WHENEVER THE SEWING MACHINE PRESSER FOOT IS RAISED AND OPERATIVE TO PERMIT LOWERING OF SAID AUXILIARY FEED DOG AND DISENGAGE FROM SAID DRIVE MEANS WHENEVER THE SEWING MACHINE PRESSER FOOT IS LOWERED, SPRING MEANS OPERATIVE TO RESILIENTLY BIAS SAID AUXILIARY FEED DOG TOWARD SAID SEWING MACHINE FEED DOG, AND MEANS FOR SYNCHRONIZING THE FOUR WAY FEED MOTION OF THE AUXILIARY FEED DOG WITH THE FOUR WAY FEED MOTION OF THE SEWING MACHINE FEED DOG TO CAUSE BOTH SAID FEED DOGS TO MOVE THE MATERIAL BEING STITCHED IN THE SAME DIRECTION AND SUBSTANTIALLY SIMULTANEOUSLY WHEN SUCH MATERIAL IS ENGAGED THEREBY. 